This core will provide state-of-the-art bioimaging support for projects 1, 2, and 3, J. Zheng, H. Gendelman, and Y. Persidsky. The work will include quantitative magnetic resonance imaging (MRI), MR spectroscopic imaging (MRSI), and single photon emission computed tomography (SPECT). Two 7-Tesla small animal MRI/S systems, now operative at the University of Nebraska Medical Center, will provide quantitative neuroimaging and superparamagnetic iron oxide (SPIO) labeled cell tracking for rodent neuroAIDS animal models of HIV-1 associated dementia (HAD). One GammaMedica Ideas animal SPECT will be used in determining biodistribution of gamma emitter labeled cells or molecular probes and provides an excellent complement to MRI cell tracking methods. The image-processing laboratory has developed custom MRI/SPECT animal holders incorporating visible fiducial markers to allow coregistration of these two modalities. This allows anatomical details for SPECT images and validation of cell quantification by MRI. The bioimaging core methods also include quantitative mapping of blood-brain barrier permeability (project 3, Y. Persidsky), quantitative arterial spin labeled perfusion mapping, and quantitative proton MRSI (1H MRSI) (projects 2 and 3, H. Gendelman and Y. Persidsky). In addition, advanced imaging and spectroscopic analysis methods have been developed within the MRI/S core facility to allow automated mouse brain subimaging and coregistration/warping of imaging results with histology (all projects). This core will also support developmental therapeutics relevant to microglial activation in HAD. The long-term aims of these works are to assess the physiological MRI and biochemical 1H MRSI predictors of neuropathology and cell migration dynamics (MRI and SPECT) in mouse models of neuroAIDS. This will provide sensitive and specific screens of the onset and/or progression of disease as well as providing response kinetics to a variety of therapeutic interventions. The results obtained from this core will have direct applicability for monitoring the course of human neurodegenerative disorders. Significant modifications of the core were made in both focus and design so that it can unambiguously provide novel data that cannot readily be btained by histopathological examinations alone.